Antenna system

• US 20080012774A1
• Filed: 07/12/2006
• Published: 01/17/2008
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Wang, Shu-Li
• Granted Patent: US 7,773,041 B2
• Time in Patent Office: Days
• US Class Current: 343/702
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/265 Open ring dipoles; Circular dipoles

Abstract

An antenna system includes a dielectrically-loaded loop element electromagnetically coupled to a planar element. The antenna system exhibits uniform, broadband radiation and reception patterns.

Claims

1. An antenna system, comprising:

a dielectrically-loaded loop element; and

a substantially planar element coupled with the dielectrically-loaded loop element, wherein the substantially planar element is disposed substantially parallel to a major axis of the dielectrically-loaded loop element, substantially perpendicular to a minor axis of the dielectrically-loaded loop element.

2. The antenna system of claim 1, wherein the dielectrically-loaded loop element comprises a loop element enclosing a printed circuit board (PCB) assembly.

3. The antenna system of claim 1 wherein the major axis of the dielectrically-loaded loop element is disposed substantially parallel to an edge of the substantially planar antenna element and substantially parallel to a face of the substantially planar element.

4. The antenna system of claim 2, wherein the dielectrically-loaded loop element comprises a first conductor on a first side of the PCB assembly and a second conductor on a second side of the PCB assembly, wherein the first conductor and the second conductor are connected by one of a plated feed-through and a PCB wrap-around.

5. The antenna system of claim 1, wherein the dielectrically-loaded loop element comprises a first section and a second section coupled to the first section, the first section comprising a printed conductor on a printed circuit board (PCB) assembly and the second section comprising a printed conductor on a flexible printed circuit, wherein the flexible printed circuit is configured to conform to a component of the PCB assembly.

6. The antenna system of claim 1, wherein the substantially planar element comprises a metallic back plate of an enclosure of the printed circuit board assembly, and wherein the enclosure of the printed circuit board assembly includes a non-metallic front cover.

7. The antenna system of claim 1, wherein the substantially planar element has one of a substantially rectangular footprint, a substantially square footprint, a substantially circular footprint, a substantially semi-circular footprint and a substantially elliptical footprint.

8. The antenna system of claim 7, wherein the substantially planar element is dielectrically loaded, wherein a principle dimension of the substantially planar element is approximately one wavelength at a center frequency of the antenna system.

9. The antenna system of claim 7, wherein the substantially planar element is dielectrically loaded, wherein a principle dimension of the substantially planar element is approximately one-half wavelength at a center frequency of the antenna system.

10. The antenna system of claim 1, wherein the dielectrically-loaded loop element comprises an aperture having an aspect ratio approximately equal to or greater than 7:

1 and an electrical length approximately less than or equal to one wavelength at a center frequency of the antenna system.

11. The antenna system of claim 10, wherein the dielectrically-loaded loop element is separated from the substantially planar element by less than or equal to approximately one-fortieth of a free-space wavelength at the center frequency of the antenna system

12. The antenna system of claim 10, wherein a return loss of the antenna system is greater than or equal to approximately 8 decibels (dB) over an approximately 13 percent bandwidth, wherein an average azimuth gain of the antenna system is approximately −

2.6 dB relative to an isotropic radiator (dBi) at a center frequency of the antenna system, and wherein an elevation pattern of the antenna system is characterized by a peak gain of approximately 0 dBi and a half-power beamwidth of approximately 60 degrees.

13. A portable media player, comprising:

an antenna system, comprising;

a dielectrically-loaded loop element; and

a substantially planar element coupled with the dielectrically-loaded loop element, wherein the substantially planar element is disposed substantially parallel to a major axis of the dielectrically-loaded loop element, substantially perpendicular to a minor axis of the dielectrically-loaded loop element;

a radio frequency (RF) transceiver coupled with the antenna system to transmit and receive media;

a media processing system coupled with the RF transceiver to process the media;

a storage device coupled to the media processing system to store the media; and

one or more input-output devices to provide a user interface and to present the media to a user.

14. A portable media player as in claim 13, wherein the media comprises one or more of music and video and wherein the one or more input-output devices comprises a click wheel selection device to select the media stored on the storage device, and wherein the media processing system is disposed within a PCB within a volume defined by the substantially planar element, and wherein a display device is coupled to the media processing system to display indicators of media being selected through the click wheel selection device.

15. A wireless device, comprising:

an antenna system, comprising;

a dielectrically-loaded loop element; and

a substantially planar element coupled with the dielectrically-loaded loop element, wherein the substantially planar element is disposed substantially parallel to a major axis of the dielectrically-loaded loop element, substantially perpendicular to a minor axis of the dielectrically-loaded loop element;

a digital radio frequency (RF) transceiver coupled to the antenna system to send and receive at least one of digital voice signals and digital data signals via the antenna system;

a digital processing system coupled with the transceiver to control the transceiver and manage the digital signals;

a storage device coupled with the digital processing system to store data; and

one or more input-output devices to provide a user interface.

16. The wireless device as in claim 15, wherein the one or more input-output devices comprise at least one of an LCD display, a keypad and an audio transducer, and wherein the digital processing system and the transceiver are disposed on a PCB within a volume defined by the substantially planar element.

17. A portable device having an antenna structure therein, comprising:

a generally U-shaped element; and

a support element having a substantially planar portion, wherein the substantially planar portion has an electrical length along a first dimension proximate to one-half wavelength of a frequency of interest, and an electrical length along a second dimension proximate to one wavelength of a frequency of interest, wherein the support element is a conductive element located within an induction field region of the loop element.

18. A method of manufacturing an antenna system, comprising:

printing a first portion of a loop element on a printed circuit board (PCB);

printing a second portion of the loop element as a trace on a flexible circuit;

loading the PCB with PCB components to fabricate a PCB assembly;

attaching the second portion of the loop element to the first portion of the loop element;

forming the second portion of the loop element to the PCB assembly; and

,

mounting the PCB assembly within a support element having a substantially planar portion.